Biomimetic Shark-Skin Riblet Hydrodynamic Drag Reduction

The time gain is the optimistic end of the range and should be read sceptically: it assumes constant power output and converts drag to speed by the cube law, while a real swimmer is dominated by pressure and wave drag rather than skin friction, so the friction saving computed here acts on only a fraction of total resistance. The reduction curve is a symmetric fit about the optimum, whereas measured riblet performance falls off more gently below the optimum than above it. Flat-plate friction also flatters a swimmer, who is neither flat nor steady. Competition swimwear is governed by strict equipment rules — check the current regulations before pursuing any surface texture.